Rapid radiometric methods to detect and differentiate Mycobacterium tuberculosis/M. bovis from other mycobacterial species

Rapid methods for the differentiation of Mycobacterium tuberculosis/M. bovis (TB complex) from other mycobacteria (MOTT bacilli) were developed and evaluated in a three-phase study. In the first phase, techniques for identification of Mycobacterium species were developed by using radiometric technology and BACTEC Middlebrook 7H12 liquid medium. Based on 14CO2 evolution, characteristic growth patterns were established for 13 commonly encountered mycobacterial species. Mycobacteria belonging to the TB complex were differentiated from other mycobacteria by cellular morphology and rate of 14CO2 evolution. For further differentiation, radiometric tests for niacin production and inhibition by Q-nitro-alpha-acetyl amino-beta-hydroxy-propiophenone (NAP) were developed. In the second phase, 100 coded specimens on Lowenstein-Jensen medium were identified as members of the TB complex, MOTT bacilli, bacteria other than mycobacteria, or "no viable organisms" within 3 to 12 (average 6.4) days of receipt from the Centers for Disease Control. Isolation and identification of mycobacteria from 20 simulated sputum specimens were carried out in phase III. Out of 20 sputum specimens, 16 contained culturable mycobacteria, and all of the positives were detected by the BACTEC method in an average of 7.3 days. The positive mycobacterial cultures were isolated and identified as TB complex or MOTT bacilli in an average of 12.8 days. The radiometric NAP test was found to be highly sensitive and specific for a rapid identification of TB complex, whereas the radiometric niacin test was found to have some inherent problems. Radiometric BACTEC and conventional methodologies were in complete agreement in Phase II as well as in Phase III.     

Influence of early or late dietary restriction on life span and immunological parameters in MRL/Mp-lpr/lpr mice.

Reduced food intake doubles and even triples the life span of (NZB X NZW)F1 (B/W) mice and greatly influences of food intake while keeping vitamin and mineral intake constant in mice of the MRL/Mp-lpr/lpr (MRL/l) strain. Restriction of food intake greatly prolongs life. This influence also was seen when dietary restriction was imposed later in life. Dietary restriction inhibited development of lymphoproliferative disease and greatly decreased the numbers of cells in thymus, lymph nodes, and spleen. It also delayed development of glomerulonephritis and maintained certain immunological responses. Proliferative responses to phytohemagglutinin, pokeweed mitogen, or allogeneic spleen cells were maintained in the mice fed a low-calorie diet from 6 wk. Imposing diet at 12 wk had a lesser influence than earlier restriction. These dietary influences did not depress formation of anti-DNA antibodies or circulating immunocomplexes. MRL/l mice show an apparently extremely low production of interleukin 2, and dietary restriction increased the capacity of lymph node cells but not spleen cells to produce this immunomodulator.     

Unintended consequences of policy change to watchful waiting for asymptomatic inguinal hernias

Introduction

In 2009 the Department of Health instructed McKinsey & Company to provide advice on how commissioners might achieve world class National Health Service productivity. Asymptomatic inguinal hernia repair was identified as a potentially cosmetic procedure, with limited clinical benefit. The Birmingham and Solihull primary care trust cluster introduced a policy of watchful waiting for asymptomatic inguinal hernia, which was implemented across the health economy in December 2010. This retrospective cohort study aimed to examine the effect of a change in clinical commissioning policy concerning elective surgical repair of asymptomatic inguinal hernias.

Methods

A total of 1,032 patients undergoing inguinal hernia repair in the 16 months after the policy change were compared with 978 patients in the 16 months before. The main outcome measure was relative proportion of emergency repair in groups before and after the policy change. Multivariate binary logistic regression was used to adjust the main outcome for age, sex and hernia type.

Results

The period after the policy change was associated with 59% higher odds of emergency repair (3.6% vs 5.5%, adjusted odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.03–2.47). In turn, emergency repair was associated with higher odds of adverse events (4.7% vs 18.5%, adjusted OR: 3.68, 95% CI: 2.04–6.63) and mortality (0.1% vs 5.4%, p<0.001, Fisher’s exact test).

Conclusions

Introduction of a watchful waiting policy for asymptomatic inguinal hernias was associated with a significant increase in need for emergency repair, which was in turn associated with an increased risk of adverse events. Current policies may be placing patients at risk.     

New insights into necrotizing enterocolitis: From laboratory observation to personalized prevention and treatment

Background/purpose

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity that develops after feeding, often without warning, and results in diffuse intestinal necrosis leading to sepsis and death in many cases. The lack of improvement in overall survival is influenced by nonspecific diagnostic modalities as well as inexact and nonpersonalized treatment strategies.

Silencing is Not-So Golden: A New Model for Inheritance of Lynch Syndrome

Heritable somatic methylation and inactivation of MSH2 in families with Lynch syndrome due to deletion of the 3' exons of TACSTD1
Ligtenberg et al. (2009)
Nature Genetics 41: 112–117     

Optic neuritis in children with poor recovery of vision.

We reviewed the records of 10 children with optic neuritis in whom recovery of vision was poor or incomplete. Our cases were otherwise similar to those described in previous studies in that they were always bilateral, often accompanied by a viral prodrome (seven of 10), and usually associated with disc oedema (seven of 10). Seven of twenty eyes had a final visual acuity of 6/60 or worse and only one patient regained 6/6 vision in either eye. In three patients the best vision in either eye was 6/60 or worse. Recovery of vision was often slow, taking up to six years. Five of 10 patients have developed multiple sclerosis (MS), and one child had acute disseminated encephalomyelitis (ADEM) with optic neuritis. Optic neuritis in children does not always carry a good prognosis for recovery of vision; however, the failure of vision recovery in a short period of time does not necessarily indicate a poor outcome. Some children with optic neuritis develop MS, which can develop even when optic neuritis follows a viral illness.     

A nationwide survey on the prevalence of atrioesophageal fistula after left atrial radiofrequency catheter ablation

BACKGROUND: There are limited data on the prevalence of atrioesophageal fistula (AEF) after left atrial radiofrequency catheter ablation for atrial fibrillation (AF). The purpose of this study was to determine the prevalence and factors associated with AEF using a nationwide anonymous survey. METHODS AND RESULTS: The information solicited included the practice setting, number of left atrial ablations performed for AF, prevalence of AEF, clinical presentation and outcome of these patients, ablation strategy, type of ablation catheter, and energy settings used to deliver radiofrequency energy. The survey was mailed to 1,874 members of the Heart Rhythm Society within the US and 585 physicians responded (31%). AEF was reported in six of the 20,425 patients who underwent a left atrial ablation procedure (0.03%). All six patients suffered from major cerebrovascular events. Five of the six patients died (83%). The patient who survived had residual hemiparesis. There was no association between the risk of AEF and the case volume. In five patients, wide area circumferential ablation was performed. In the remaining patient, pulmonary vein isolation by ostial ablation was employed. In all cases an 8-mm tip ablation catheter was used. The power in patients who did and did not develop AEF were 58 +/- 13 and 41 +/- 9 W, respectively (P = 0.03). In one patient AEF occurred despite <1 degrees C rise recorded from an esophageal temperature probe. In the remaining patients no specific method was used to visualize the location of the esophagus. CONCLUSIONS: Based on the responses to the survey, the risk of AEF appears to be <1%. However, AEF is associated major cerebrovascular events and leads to death in >80% of the patients.     

Clinical features and outcome in childhood T-cell leukemia-lymphoma according to stage of thymocyte differentiation: a Pediatric Oncology Group Study

The immunophenotypes of lymphoblasts from children with newly diagnosed T-cell acute lymphoid leukemia (T-ALL, n = 101) or T-cell non-Hodgkin lymphoma (T-NHL, n = 31) were analyzed to correlate stage of thymocyte differentiation with clinical features and outcome. The 67 boys and 34 girls with T-ALL were 1 month to 18 years old (median, 8 years) with leukocyte counts ranging from 2 to 810 x 10(9)/L (median, 55 x 10(9)/L). Eighteen of these patients were black, and 70 had a mediastinal mass. Twenty-six boys and five girls with a median age of 9 years (range, 1 to 20 years) had T-NHL. Seven of these patients were black, and 24 had a mediastinal mass. The distributions of thymocyte developmental stages (early [CD7+], intermediate [CD1+ and/or CD4+ and/or CD8+], and mature [CD3+]) in cases of T-ALL and T-NHL were significantly different: 34%, 43%, and 23% v 6%, 62%, and 32% (P = .02). A comparison of the patients' clinical features according to the maturational stage of thymocytes failed to disclose significant differences in the majority of characteristics studied. However, patients with mature-stage T-NHL, with or without the addition of subjects with mature-stage T-ALL, were less likely to have a mediastinal mass (P = .02 for both comparisons). Those with intermediate-stage T-cell malignancy (T-ALL and T-NHL combined) were the subgroup most likely to have a mediastinal mass (P = .01). Response to remission induction therapy was significantly worse in the T-ALL subgroup with an early-stage phenotype: a failure rate of 21% v 0% and 6% for the two more differentiated phenotypic subgroups (P = .007). Event-free survival was not affected by thymocyte maturational stage in cases of either T-ALL or T-NHL. Despite evidence of clinical heterogeneity among the maturational stages of T-cell malignancies in children, these developmental subdivisions do not appear to be critical determinants of outcome once remission is achieved. We conclude that such phenotypes need not be included in the stratification plans for clinical trials using common induction treatment.